textproduct: Quad Cities

KEY MESSAGES

- There are chances for showers and storms late tonight into Friday morning and again on Saturday night. Rainfall amounts will be light with less than a quarter of an inch expected for the two storm systems. There is a Marginal (level 1 out of 5) Risk of severe storms Saturday afternoon into Saturday night.

- A pattern change this weekend will bring heat and high humidity to the area and persist through next week. The probability of heat headlines continues to increase (50-70% chance) with the possibility of heat indices over 100.

SHORT TERM /THROUGH FRIDAY/

Issued at 105 PM CDT Thu Jun 25 2026

Quiet weather across the area late this afternoon and evening ahead of a shortwave and surface low that is forecast to move across the area after 06 UTC Friday and exit the area on Friday afternoon. Clouds will be on the increase tonight with increasing lift and moisture after 3 AM. Scattered showers and isolated thunderstorms will slowly spread northward overnight after 06 UTC with the best chances of showers and storms 12 UTC to 18 UTC Friday mainly along and south of a Fairfield to Galesburg line. There are differences between the models on how far north precipitation is forecast to spread with decreasing chances northward from Interstate 80 to Highway 30. The better lift and moisture shifts eastward after 18 UTC with precipitation quickly ending east of the Mississippi River. The probability of seeing more than two tenths of an inch rain south of a Fairfield to Galesburg line is 20 to 30 percent with the probability decreasing to 10 percent along the Interstate 80 corridor.

Due to precipitation and cloud cover, high temperatures on Friday will be lower and mainly range from 70 to 75 degrees with the cooler temperatures in far southeast Iowa, far northeast Missouri and west central Illinois.

LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/

Issued at 105 PM CDT Thu Jun 25 2026

Zonal flow is forecast to continue through Saturday. Shortwave ridging is forecast Friday night into Saturday before a shortwave trough moves across the area Saturday afternoon and night. A low level jet develops Saturday evening with speeds of 10 to 20 knots and there is building instability of 1000 to 1500 J/KG across the area. There is also around 30 knots of 0 to 6 km shear. For this reason, the Storm Prediction Center has a Marginal (level 1 out of 5) Risk of severe storms south of a Fairfield to Galesburg line with the primary threats being damaging winds and hail. Any rainfall amounts will be light with less than two tenths of an inch expected.

Sunday through the reminder of the long term period shows ridging building northward into the area with a closed 500 MB 594 height contour centered to our southeast through Sunday. This will bring warming south to southwesterly flow into the area. The NBM is showing quickly increasing temperatures into the lower to mid 90s across much of the area Sunday through the 4th of July. The probability across much of the area to see high temperatures greater than 90 degrees during that period is 40 to 70 percent with mean height indices over 100 degrees each day. These temperatures are 2 to 3 standard deviations above model normals for late June into early July. Models do show westward shift in the center of high pressure directly over the area midweek onward. Sunday through through Tuesday with the high to out southeast and lee troughing occurring along the front range there is a tighter pressure gradient across the area with the potential for breezy conditions each of the days.

Beyond Tuesday, where high pressure is located will be critical to the forecast with deep southwesterly flow aloft to our west. If this is farther to the east than is currently forecast we will be closer to the main storm track which may result in increasing chances for showers and storms across the area midweek onward with strong instability due to the high heat and humidity. This may also lead to heavy rainfall across the area if storms do occur.

A excessive heat watch may be needed in the coming days for Sunday through much of next week with the potential for heat indices over 100 every day if the current trends continue.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 632 PM CDT Thu Jun 25 2026

VFR conditions are expected to continue through 26/008Z area-wide. Past 26/08Z, showers on the northern edge of a cluster of storms will move into the southern half of the area, reaching BRL by 26/09Z. MVFR CIGs are expected with heavier rainfall, with uncertainty in the northern extent. As such, PROB30s have ben kept for CID and MLI, with MLI having higher confidence than CID. Once showers depart, low ceilings around 4000 ft will remain through the end of the period.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.